Repair windows 8.1 boot through Debian

jumpuos · 03-28-2016, 10:32 PM

I screwed up my Windows 8.1 boot with Easybcd. I checked some box that said count down from 5 seconds in the edit boot section now if I boot in UEFI boot it says windows cannot boot insert repair disk and if you don't have the repair disk contact manufacturer. If I boot in CSM boot mode I can get to Debian 8 grub menu but windows is not on it. I want to use Grub customizer to be able to boot windows and maybe have windows show up on the Debian grub menu if it is not to risky. I cant even see window with the grub customizer program.

robertbas · 03-29-2016, 01:58 AM

boot into debian, open a terminal, su, update-grub

yancek · 03-29-2016, 08:00 AM

Quote:

If I boot in CSM boot mode I can get to Debian 8 grub menu but windows is not on it

That sounds like windows is installed UEFI and Debian is not. Read the first part of the page at the link below through the General Principles section which explains why mixing MBR and UEFI won't work. It is an Ubuntu doc page but the first part applies to UEFI in general. If that's not the case, post more details. Get the bootinfoscript and run it and post the output.

https://help.ubuntu.com/community/UEFI

https://github.com/arvidjaar/bootinfoscript

jefro · 03-29-2016, 07:37 PM

Did it ever work correctly?

Did it boot to grub then chain to windows?

When you boot to a live media do you see windows partitions?

DaneM · 03-30-2016, 03:34 AM

I struggled with this problem for a long time when I recently tried to install Ubuntu alongside Windows 10, on an EFI BIOS. The solution I found is as follows--but it's entirely from memory, so YMMV.

Reboot into a live USB or DVD.

Open a command prompt.

Type the following:

Code:

sudo blkid
(Note the device nodes of your Linux boot and system partitions. It will be something like "/dev/sdXY", where "X" is a letter, and "Y" is a number.)
sudo mount [Linux system partition] /mnt
sudo mount [Linux boot partition] /mnt/boot/efi
sudo mount --bind /dev /mnt/dev
sudo mount --bind /sys /mnt/sys
sudo mount --bind /proc /mnt/proc
sudo mount --bind /var /mnt/var
sudo mount --bind /tmp/mnt/tmp
sudo chroot /mnt
sudo grub-install [Linux boot partition]
sudo update-grub
exit

Reboot.

Go into EFI BIOS and ensure that it's booting from your Linux hard drive.

Please note that GRUB must be installed into the Ubuntu Linux boot partition, when using EFI. If you install to the drive root (/dev/sdX rather than /dev/sdXY), you'll have problems.